Method and forming device for producing a packaging element

Abstract

A method for manufacturing a packaging element (1) comprising at least the following steps: a) providing a preform (2) consisting at least partially of a fiber-based packaging material in a forming device (3); b) holding the preform (2) in a drawing slot (5) of the forming device (3) by means of a blank holder (4) with a holding force (29); c) forming the preform (2) into the packaging element (1) with the forming device (3); and d) calibrating a sealing edge (6) of the packaging element (1) after step c) by the blank holder (4) with a calibration force (30) that is greater than the holding force (29). Furthermore, a forming device for manufacturing a packaging element (1) is proposed.

Description

[0001] The present invention relates to a method and a forming device for producing a packaging element. The packaging element is particularly suitable for use as packaging for a packaged product or for producing such a packaging.

[0002] The packaging element can be designed, for example, as a bowl, cup, or mug. The packaging element can have a receiving cavity for the packaged product. The receiving cavity can be filled with a packaged product, for example a liquid or a powder, such as coffee grounds. After the receiving cavity has been filled with the packaged product, the receiving cavity can be closed with a seal, in particular a peelable seal. The seal can seal the packaged product in the receiving cavity, in particular in a gas-tight manner. The seal can be a film, for example. The packaging element can have a sealing edge to which the seal can be attached. The seal can be attached, for example, by a welded or adhesive connection.

[0003] During the production of the packaging element, a preform, for example in the form of a blank or a round blank, can be formed into the packaging element using a forming device. During forming, the preform is clamped or arranged in a drawing gap between a hold-down device and a die. The preform is then drawn into the die with a punch in the area of ​​a future base of the packaging element or in the area of ​​the future base of the receiving cavity, whereby material from the preform can flow from the drawing gap into the die. During forming, the receiving cavity is created in a drawing section of the packaging element and a circumferential sealing edge is created at an upper end of the packaging element. The circumferential sealing edge can be undefined and / or uneven, in particular due to uneven flow of the preform material from the drawing gap and / or due to wrinkling.The undefined seal edge can make it difficult to tightly attach the seal to the seal edge.

[0004] Based on this, the object of the present invention is to at least partially solve the problems described with reference to the prior art and, in particular, to provide a method for producing a packaging element with which irregularities in the sealing edge can be at least reduced. Furthermore, a forming device for producing a packaging element with which irregularities in the sealing edge can be at least reduced is to be provided.

[0005] These objects are achieved by a method and a forming device according to the features of the independent claims. Further advantageous embodiments are specified in the dependent claims as well as in the description and, in particular, in the description of the figures. It should be noted that those skilled in the art can combine individual features in a technologically expedient manner, thereby achieving further embodiments of the invention.

[0006] A method for producing a packaging element which comprises at least the following steps contributes to this: a) Providing a preform consisting at least partially of a fiber-based packaging material in a forming device; b) Holding the preform down by means of a hold-down device in a drawing gap of the forming device with a hold-down force; c) Forming the preform into the packaging element by means of the forming device; and d) Calibrating a sealing edge of the packaging element after step c) by the hold-down device with a calibration force that is greater than the hold-down force.

[0007] The packaging element can be used in particular as packaging for a packaged product and / or for producing packaging for the packaged product. The packaging element can be, for example, a bowl, a pod, or a cup.

[0008] In step a), a preform consisting at least partially of a fiber-based packaging material is provided in a forming device. The provision can be carried out, for example, using a conveyor device, in particular an automatic one. The preform can be a blank and / or a round plate. The preform can be flat and / or have a material thickness of, for example, 0.1 mm [millimeters] to 2 mm. The preform can have a round cross-section. The preform can have a diameter of, for example, 20 mm to 300 mm or an edge length of, for example, 20 mm to 300 mm. The fiber-based packaging material can comprise fibers of plant origin and / or cellulose. The fiber-based packaging material can be, for example, paper, cardboard or carton. The fiber-based packaging material has particular advantages with regard to recyclability.The preform may have a coating made of at least one additional material and / or be impregnated with at least one additional material. The coating may be formed, for example, on an inner and / or outer side of the preform. The coating may form a barrier layer.

[0009] The forming device can be a deep-drawing press. The forming device can comprise a punch, a die and / or a hold-down device. The hold-down device is adjustable in particular between a hold-down position and a release position along a hold-down device travel path. The hold-down device travel path can be straight and / or vertical. The hold-down device can be made at least partially of metal. The hold-down device can be designed at least partially in the manner of a plate or a ring. The hold-down device has in particular a punch opening for the punch, through which the punch can be at least partially adjusted into the forming cavity of the die. The hold-down device can have a hold-down surface. The hold-down surface is in particular at least partially flat. The hold-down device or the hold-down surface of the hold-down device at least partially delimit the drawing gap.The drawing gap extends in particular around the at least one forming cavity. The drawing gap can be formed at least partially between the hold-down device and the die. The hold-down device can be made at least partially of metal and / or surround the punch. The hold-down device can have a punch opening for the punch. The hold-down device can be electrically, hydraulically or pneumatically adjustable between the hold-down position and the release position. The hold-down device is adjustable in particular relative to the die and / or independently of the punch. The die can have at least one forming cavity. The die is in particular made at least partially of metal. The die or the at least one forming cavity can at least partially form a negative of a mold or an outer shape of the (to be produced and / or formed) packaging element.The at least one forming cavity can be configured as an opening, drawing opening, and / or trough. The at least one forming cavity can be formed in an upper outer surface of the die. The upper outer surface of the die can be flat.

[0010] After step a), in step b) the preform is held down in a drawing gap of the forming device using the hold-down device with a hold-down force. For this purpose, the hold-down device is adjusted to the hold-down position. In the hold-down position, the preform is clamped in the drawing gap, in particular between the hold-down device and the die. In the hold-down position, the drawing gap can have a gap width (in particular in a vertical direction) which in particular corresponds (essentially) to a material thickness of the preform. The gap width can be, for example, 0.1 mm to 2 mm. The hold-down device is pressed onto the preform with a hold-down force which enables the preform to flow and / or slip out of the drawing gap towards the forming cavity of the die. The hold-down force can be, for example, 1 N [Newton] to 200 N.The hold-down force can be generated using a pressing device on the forming device.

[0011] In step c), the preform is formed into the packaging element by means of the forming device. The forming takes place while the preform is held down in the drawing gap by means of the hold-down device with the hold-down force. The hold-down force can be varied during the forming of the preform, for example depending on the position of the punch. This allows the subsequent flow and / or slippage during the forming of the preform to be (specifically) varied or controlled. To form the preform, the punch can be adjusted to a forming position, in particular into the at least one forming cavity of the die. During forming, the punch draws the preform, in particular partially, into the at least one forming cavity of the die. The forming process creates, in particular, a receiving cavity of the packaging element for the packaged goods. During forming, the preform can be formed or deep-drawn into the packaging element by plastic deformation.The punch can, for example, be designed as a male mold, a deep-drawing punch, or a stamping die. A punch shape of the punch can be at least partially adapted to a shape of the at least one forming cavity. The punch can be driven or adjusted electrically, hydraulically, and / or pneumatically, for example by means of a punch drive. The punch is adjustable, in particular, relative to the die, in particular along a punch travel path and / or between an initial position and the forming position. The punch travel path can be straight and / or vertical. During forming, a sealing edge of the packaging element, in particular a circumferential one, is created in the drawing gap, in particular from an edge of the preform. The sealing edge can, for example, have a sealing edge width of 0.5 mm [millimeters] to 10 mm. The sealing edge width can, in particular, be (substantially) constant along the sealing edge.A seal for closing the receiving cavity of the packaging element can be attached to the sealing edge, for example, by means of an adhesive and / or welded connection. The seal can be designed, for example, as a film. The receiving cavity can be closed by the seal in a fluid-tight, gas-tight, and / or airtight manner.

[0012] In step d), the sealing edge of the packaging element is calibrated after step c) by the hold-down device with a calibration force that is greater than the hold-down force. Step d) is in particular only carried out after the preform has been completely formed in step c) and / or after the punch has been completely adjusted into the forming position in step c). During calibration, the hold-down device is pressed with the calibration force onto the sealing edge of the packaging element in the drawing gap and / or in particular the sealing edge of the packaging element is clamped in the drawing gap, in particular between the hold-down device and the die, with the calibration force. The calibration force is greater than the, in particular maximum, hold-down force during step c).The calibration in step d) can be carried out with a calibration force that is (in particular considerably) greater than a hold-down force that (still) allows sufficient flow and / or sufficient slippage of the preform out of the drawing gap in step c). In other words, the calibration in step d) can be carried out with a calibration force that is (in particular considerably) greater than a maximum permissible hold-down force in step c). The maximum permissible hold-down force in step c) is a hold-down force that, if exceeded, will cause cracks in the packaging element when the preform is formed into the packaging element. The calibration force can be generated by means of the pressing device of the forming device.

[0013] By calibrating the sealing edge with the calibration force, wrinkles that occurred in the sealing edge of the packaging element during the forming process in step c) can be at least partially or completely smoothed out. This can prevent leaks when attaching the seal to the sealing edge.

[0014] The calibration force can be at least twice the hold-down force (maximum in step c). The calibration force can preferably be at least ten times, at least one hundred times, or at least one thousand times the hold-down force (maximum in step c).

[0015] The calibration force can be at least 0.5 kN (kilonewton). The calibration force can preferably be at least 1 kN, at least 5 kN, at least 10 kN, at least 50 kN, or at least 100 kN. The calibration force can in particular be up to 120 kN. The calibration force can be, for example, 0.5 kN to 120 kN, 1 kN to 120 kN, 5 kN to 120 kN, 10 kN to 120 kN, 50 kN to 120 kN, or 100 kN to 120 kN.

[0016] Calibration can be performed with a calibration time of 1 second to 10 seconds.

[0017] According to a further aspect, a forming device for producing a packaging element is also proposed, which has at least the following: a punch for forming a preform into the packaging element; a hold-down device for holding the preform down with a hold-down force in a drawing gap during forming; a pressing device for the hold-down device; a controller for controlling the pressing device, which is designed and provided to calibrate a sealing edge of the packaging element by the hold-down device with a calibration force that is greater than the hold-down force after the preform has been formed into the packaging element.

[0018] The forming device and / or the control system can be used to carry out the method described here or can be configured and / or provided to carry out the method described here.

[0019] The clamping device can be an electric, hydraulic, and / or pneumatic clamping device. The clamping device allows the hold-down device to be adjusted, particularly between the release position and the hold-down position, along the clamping device's travel path. The clamping device can be used, in particular, to generate the hold-down force and / or the calibration force of the hold-down device.

[0020] The forming device may comprise a device for variable configuration (spacing) of the drawing gap during forming. The forming device may comprise a device for adjusting the gap width of the drawing gap during forming. The gap width may be dimensioned, in particular, in a vertical direction and / or parallel to the punch travel path.

[0021] The control system is, in particular, an electronic control system. The control system can comprise at least one microprocessor. The control system can, in particular, control the adjustment of the blank holder along the blank holder travel path, the level of the blank holder force, and / or the level of the calibration force. The control system can be configured and / or provided to control the forming device. In particular, steps a), b), c), and / or d) of the method can be at least partially (in particular automatically) controllable or carried out by the control system. The control system can be connected to the pressing device and / or the punch drive in a data-conducting manner.

[0022] The pressing device can have a shaft with at least one eccentric section. The shaft can be made at least partially of metal. The shaft can be rotatable about an axis of rotation by means of a drive, for example an electric motor. The shaft can be connected to a rotor of the drive, for example at a longitudinal shaft end of the shaft. The connection between the shaft and the rotor can be made via a coupling. The drive can be controllable by the control system of the forming device. The shaft can have a shaft length of, for example, 100 mm to 1,000 mm (in particular parallel to the axis of rotation). The shaft can have at least one bearing section. The at least one bearing section can have a bearing section diameter of, for example, 10 mm to 100 mm (in particular orthogonal to the axis of rotation). The shaft can be connected to the at least one bearing section in at least one rotary support bearing of the forming device ora machine frame of the forming device. The at least one rotary support bearing can be, for example, a roller bearing. The shaft and / or the at least one rotary support bearing can be fixedly attached to the machine frame of the forming device.

[0023] The at least one eccentric section can have a circular cross-section (in particular orthogonal to the axis of rotation) whose center lies outside the axis of rotation of the shaft. The at least one eccentric section can have an eccentric section diameter of, for example, 15 mm to 150 mm. By means of the at least one eccentric section, a rotational movement of the shaft about the axis of rotation can be converted into a translational movement of the hold-down device along the hold-down travel path. The further the at least one eccentric section of the shaft is rotated in the direction of the die, in particular by means of the control and / or by means of the drive, the further the hold-down device can be moved in the direction of the die and / or into the hold-down position.The further the at least one eccentric section of the shaft is rotated toward the die, in particular by means of the control and / or the drive, the greater the hold-down force with which the hold-down device is pressed onto the preform and / or the greater the calibration force with which the hold-down device is pressed onto the sealing edge of the packaging element. Particularly high calibration forces can be generated by means of the shaft.

[0024] The shaft can be rotatable about a rotational axis that runs orthogonally to the blank holder's travel path. The rotational axis can extend horizontally and / or the blank holder's travel path can extend vertically. This reduces the space required for the forming device.

[0025] The at least one eccentric section can be arranged in a pivot bearing of the hold-down device. The at least one pivot bearing can be, for example, a cam bearing or roller cam bearing.

[0026] The shaft can extend through the punch. In particular, the shaft can extend through an opening formed in the punch. The opening is designed in particular such that the punch can be adjusted along the punch travel path by means of the punch drive, while the shaft extends through the opening of the punch. The opening can be designed, for example, as an elongated hole.

[0027] It should be noted that the advantages and features described in connection with the process are also applicable and transferable to the forming device. Furthermore, the advantages and features described in connection with the forming device are also applicable and transferable to the process.

[0028] The invention and the technical context of the invention are explained in more detail below with reference to the figures. The figures show a preferred embodiment, to which the invention is not limited. It should be noted in particular that the figures, and in particular the proportions depicted in the figures, are only schematic. They show, by way of example and schematically: Fig. 1: a forming device with a hold-down device in a release position and a punch in a starting position in a longitudinal section; Fig. 2: the forming device with the hold-down device in a hold-down position and the punch in the starting position in the longitudinal section; Fig. 3: the forming device with the hold-down device in the hold-down position and the punch in a forming position in the longitudinal section; Fig. 4: the forming device with the hold-down device in the hold-down position and the punch in the starting position in the longitudinal section; Fig. 5: the forming device in the longitudinal section; and Fig. 6: a shaft of a pressing device of the forming device in a perspective view.

[0029] Fig. 1 shows a forming device 3 in a longitudinal section. The forming device 3 comprises a punch 7, a blank holder 4 and a die 18 with a forming cavity 19. The punch 7 extends through a punch opening 20 of the blank holder 4 and is located in Fig. 1 in a starting position 21. The stamp 7 is between the starting position 21 and a Fig. 3 shown forming position 22 along a vertical punch travel path 23 with a Fig. 5 shown punch drive 27. The hold-down device 4 is located in Fig. 1 in a release position 24. The hold-down device 4 is between the release position 24 and a position in the Fig. 2 bis 4 shown hold-down position 25 with a Fig. 5 shown pressing device 8 along a vertical hold-down travel path 26. If the punch 7 is in the starting position 21 and the hold-down device 4 is in the release position 24, a preform 2 can be provided in the forming device 3 in a step a). The preform 2 is a round blank. The provision of the preform 2 can be carried out by a conveyor device not shown here. The preform 2 was in Fig. 1 arranged on an upper outer surface 28 of the die 18.

[0030] Fig. 2 shows the forming device 3 after the blank holder 4 has been removed in a step b) from the Fig. 1 shown release position 24 into the hold-down position 25. In the hold-down position 25, the hold-down device 4 can hold the preform 2 in step b) in a drawing gap 5 with a hold-down force 29. The drawing gap 5 is formed between the hold-down device 4 and the upper outer surface 28 of the die 18. The punch 7 is in Fig. 2 still in the starting position 21

[0031] Fig. 3 shows the forming device 3 after the punch 2 has been removed from the Fig. 2 shown starting position 21 along the punch travel path 23 into the forming position 22. Here, the punch 7 pulls the Fig. 1 und 2 shown preform 2 into the forming cavity 19 of the die 18, so that the preform 2 is formed into a cup-shaped packaging element 1. During the forming of the preform 2 into the packaging element 1, the hold-down device 4 holds the preform 2 down with the hold-down force 29 in the drawing gap 5, so that a Fig. 2 The edge 14 of the preform 2 shown can be partially drawn from the drawing gap 5 into the forming cavity 19 of the die 18. The edge 14 remaining in the drawing gap 5 after the preform 2 has been formed into the packaging element 1 forms a sealing edge 6 of the packaging element 1.

[0032] Fig. 4 shows the forming device 3 after step c) in a step d) during the calibration of the sealing edge 6 of the packaging element 1. During the calibration of the sealing edge 6, the hold-down device 4 presses the sealing edge 6 in the drawing gap 5 onto the upper outer surface 28 of the die 18 with a calibration force 30 which is greater than that in Fig. 2 and 3 shown hold-down force 29. This at least partially smooths and / or removes wrinkles in the sealing edge 6 during the forming process in step c). After calibrating the sealing edge 6, the stamp 7 is returned to the position shown in Fig. 1 und 2 shown starting position 21 and the hold-down device 4 from the hold-down position 25 back to the Fig. 1 shown release position 24. This allows the packaging element 1 to be removed from the forming device 3.

[0033] In Fig. 5 The forming device 3 is shown in a longitudinal section with a higher level of detail. The blank holder 4 is adjustable along the blank holder travel path 26 with the pressing device 8. The pressing device 8 comprises a shaft 10, which is rotatable about a rotation axis 13 by means of an electric motor 17. The shaft 10 is connected via a coupling 36 to a rotor 37 of the electric motor 17. The electric motor 17 is controllable by a control 9 of the forming device 3. The shaft 10 has a Fig. 6 shown first bearing section 31 and one in Fig. 6 shown second bearing section 32. The shaft 10 is rotatably mounted with the first bearing section 31 in a first rotary support bearing 33 of the forming device 3 and with the second bearing section 32 in a second rotary support bearing 34 of the forming device 3. The rotary support bearings 33, 34 can be roller bearings, for example. The rotary support bearings 33, 34 are fixedly attached to a machine frame 35 of the forming device 3, which is only partially shown here. The shaft 10 has a Fig. 6 shown first eccentric section 11 and one in Fig. 6 shown second eccentric section 12. The eccentric sections 11, 12 each have (orthogonal to the axis of rotation 13) a circular cross-section whose center lies outside the axis of rotation 13. The first eccentric section 11 is arranged in a first pivot bearing 15 of the hold-down device 4 and the second eccentric section 12 is arranged in a second pivot bearing 16 of the hold-down device 4, so that a rotational movement of the shaft 10 about the axis of rotation 13 can be converted into a translational movement of the hold-down device 4 along the hold-down device travel path 26. The pivot bearings 15, 16 can be, for example, a cam bearing or roller cam bearing. The further the eccentric sections 11, 12 of the shaft 10 are rotated in the direction of the die 18, in particular by means of the control 9 and / or the electric motor 17, the further the blank holder 4 is moved in the direction of the die 18 and / or the greater the force with which the blank holder 4 in the drawing gap 5 is pressed onto the Fig. 1 und 2 shown preform 2 or pressed onto the packaging element 1.

[0034] Wave 10 extends with a Fig. 6 shown connecting section 38 through an opening 39 formed in the stamp 7. The connecting section 38 connects the Fig. 6 shown eccentric sections 11, 12 of the shaft 10. The opening 39 is designed such that the punch 7 can be adjusted along the punch travel path 23 by means of the punch drive 27. The opening 39 is designed here as an elongated hole. The punch travel path 23 of the punch 7 runs orthogonal to the rotational axis 13 of the shaft 10. The punch travel path 23 of the punch 7 runs vertically, and the rotational axis 13 of the shaft 10 runs horizontally.

[0035] Fig. 6shows the shaft 10 in a perspective view. The shaft 10 has a shaft length 40 (parallel to the rotational axis 13). The bearing sections 31, 32 each have a bearing section diameter 41, and the eccentric sections 11, 12 each have an eccentric section diameter 42.

[0036] The invention makes it possible to at least reduce irregularities in the sealing edge 6. List of reference symbols

[0037] 1 Packaging element 2 Preform 3 Forming device 4 Hold-down device 5 Drawing gap 6 Sealing edge 7 Punch 8 Pressing device 9 Control system 10 Shaft 11 First eccentric section 12 Second eccentric section 13 Rotary axis 14 Edge 15 First pivot bearing 16 Second pivot bearing 17 Electric motor 18 Die 19 Forming cavity 20 Punch opening 21 Starting position 22 Forming position 23 Punch travel path 24 Release position 25 Hold-down position 26 Hold-down travel path 27 Punch drive 28 Upper outer surface 29 Hold-down force 30 Calibration force 31 First bearing section 32 Second bearing section 33 First pivot support bearing 34 Second pivot support bearing 35 Machine frame 36 Coupling 37 Rotor 38 Connecting section 39Opening 40One shaft length 41Bearing section diameter 42Eccentric section diameter

Claims

1. A method for producing a packaging element (1), comprising at least the following steps: a) providing a preform (2) consisting at least partially of a fiber-based packaging material in a forming device (3); b) holding the preform (2) down by means of a hold-down device (4) in a drawing gap (5) of the forming device (3) with a hold-down force (29); c) forming the preform (2) into the packaging element (1) by means of the forming device (3); and d) calibrating a sealing edge (6) of the packaging element (1) after step c) by means of the hold-down device (4) with a calibrating force (30) that is greater than the hold-down force (29).

2. The method according to claim 1, wherein the calibration force (30) is at least twice as large as the hold-down force (29).

3. Method according to one of the preceding claims, wherein the calibration force (30) is at least 0.5 kN.

4. Method according to one of the preceding claims, wherein the calibration is carried out with a calibration duration of 1 second to 10 seconds.

5. A forming device (3) for producing a packaging element (1) which consists at least partially of a fiber-based packaging material, at least comprising: - a punch (7) for forming a preform (2) into the packaging element (1); - a hold-down device (4) for holding down the preform (2) with a hold-down force (29) in a drawing gap (5) during forming; - a pressing device (8) for the hold-down device (4); - a controller (9) for controlling the pressing device (8), which is designed and provided to calibrate a sealing edge (6) of the packaging element (1) by means of the hold-down device (4) with a calibration force (30) which is greater than the hold-down force (29) after the preform (2) has been formed into the packaging element (1).

6. Forming device (3) according to claim 5, wherein the pressing device (8) has a shaft (10) with at least one eccentric section (11, 12).

7. Forming device (3) according to claim 6, wherein the shaft (10) is rotatable about an axis of rotation (13) which runs orthogonally to a hold-down travel path (26) of the hold-down device (4).

8. Forming device (3) according to claim 6 or 7, wherein the at least one eccentric section (11, 12) is arranged in at least one rotary bearing (15, 16) of the hold-down device (4).

9. Forming device (3) according to one of claims 6 to 8, wherein the shaft (10) extends through the punch (7).

10. Forming device (3) according to one of claims 5 to 9, wherein the pressing device (8) has an electric motor (17).

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